Oct 02, 2019

日本物理学会北海道支部講演会

講演題目： Experimental signature of the attractive Coulomb force between positive and negative magnetic monopoles in spin ice
講 師 ： Carley PAULSEN 氏
Institute of Neel, CNRS, Grenoble, France, Director of Research
日 時 ： 令和元年10月2日 (水) 10:30~11:30
場 所 ： 室蘭工業大学 教育研究1号館 A324 室
要 旨 ：
Thermal physics, electrical engineering, chemistry and biochemistry are
essentially determined by the Coulomb interaction of quasiparticles.
Such quasiparticles are not real and cannot be interrogated by the
methods of particle physics. So how do you prove experimentally that
two quasiparticles interact via Coulomb’s law ?
In this talk I will show how this can be done for magnetic, rather than
electric
quasiparticles. By freezing spin ice to 65 mK we create (+ -) pairs of
emergent magnetic monopoles which we then separate with a magnetic field.
Our experiment is arranged to make the magnetic current exactly
analogous to an electrical current, and we observe a current that grows
exponentially
with the square root of the applied field. A non-Ohmic current that
grows exponentially with the square root of applied electric field is
well known from thermionic emission, electrolytes and semiconductors. It
is a universal signature of the attractive Coulomb force between
positive and negative electrical charges, which is revealed as the
charges are driven in opposite directions by the force of an applied
electric field.
世話人 関根 ちひろ
(sekine@mmm.muroran-it.ac.jp)
室蘭工業大学大学院工学研究科しくみ情報系領域／情報電子工学系専攻